Refining petroleum.



J. C. BLACK.

REFINING PETROLEUM.

APPLICATION FILED MAR-5. 1909.

L15A7 I Patentedfiept. 7, 1915.

JOHN C. BLACK, OF POINT RICHMOND, CALIFORNIA, ASSIGNOR TO STANDARD OIL COMPANY, A CORPORATION OF CALIFORNIA.

REFINING PETROLEUM.

Specification of Letters Patent.

Patented Sept. 7, 1915.

i To all whom it may concern Be'it known that I, J OJHN C. BLACK, a citizen of the United States of America, and a resident of Point Richmond, in the county of Contra Costa and State of California, have invented new and useful Improvements in Refining Petroleum, of which the following is a specification.

This invention relates to improvements made in refining oils; and more especially in treating petroleums of various grades or qualities for the production and manufacture on a commercial scale of oils suitable for illuminating, lubricating and other purposes where it is necessary or desirable to reduce 01' limit the proportion of the heavy hydrocarbons in the finished product for certain use.

The invention is particularly applicable to the treatment of the distillates from those grades or qualities of petroleums of which the kerosene or burning'oil fraction contains an undesirable proportion of the heavy hydrocarbons, or hydrocarbons so rich in car bon that they tend to make the oil smoke when burned in a lamp. In the production of these kerosene or burning oil fractions from different grades or qualities of crude petroleum, and particularly from the oils of California and the Pacific coast, the heavy hydrocarbons are not only of an especially smoke producing character, but they are also refractory to such a degree that the methods or processes heretofore employed to remove them are difficult and expensive, being attended by a considerable waste of material, and of the reagents used in the process, as well as involving care and labor in carrying on the operations, all of which have affected the cost of the finished product.

Especially in the production of the kerosene or burning oil fractions from the distillates of the crude petroleum of Califordinary sulfuric acid of 66 Baum, but being removable, in greater proportions' at least, by the use of stronger acids, such as' sulfuric anhydrid, are yet of such a refractory character and of such relatively great.

Viscosity thatit is found necessary to use in the operation a greater quantity of the acid than is sufficient to combine or unite with the heavy hydrocarbon compounds, re.

sulting not only in a considerable waste of ac1d-because the residue, or acid sludge, as it is termed, is not easily or economically capable of being treated to recover the acid, but alsoin a loss of some of the hydrocarbons that could be retained to advantage sometimes in the finished oil product, but are liable to be removed for the reason that their extraction and removal by the acids can not well be controlled in the operations. The sludge or waste product resulting from such acid processes, also, is found of little value for further treatment, because the acids as combined or incorporated with the extracted hydrocarbons produce chemical combinations therewith that are not easily or economically capable of further treatment to recover either the acids or the hydrocarbons.

The heavy hydrocarbons, or smoky hydrocarbons as they are also termed in this description, include not/only the aromatic compounds contained in the petroleums of California, and others of the same type, but also other petroleums containing paraffin compounds. For it should be understood that the process of this invention is applicable to the refining or treatment of both kinds or qualities of the natural product.

The present invention is based on the discovery I have made that the heavy hydrocarbons included in the aromatic compoundsand the paraffin compounds as wellwill readily yield to the action of a sulfur compound of oxygen, as sulfur dioxid (S0,) in gaseous form, if the gas be forced into the petroleum, or a distillate thereofunder pressure greater than atmospheric pressure while confined in a closed vessel in which pressure is maintained; and that by maintaining such pressure and continuing to admit the gas after absorption thereof'by the charge to a point or state of saturation when precipitation will take place, the hydrocarbons contained in the charge will be attacked and removed there from by precipitation in the order or relation of their heaviness or density, and the operation can be interrupted or suspended at any stage and the proportion of the heavy hydrocarbons remaining in the treated product can be regulated by shutting off the further supply of gas to the charge of material and Withdrawing the precipitated matter and finishing the oil product in the usual way.

treating the oil product with sulfur dioxid gas is moreover a materially different product from the waste acid sludge obtained in the processes of treating distillates above referred to, and especially in the point or feature of being se arated or resolvedinto the reagent and the drocarbon compounds, by simply raising 't e temperature of the mixture while confined in a closed vessel; this involving no chemical steps or operations, and restoring both the gas and the hydrocarbons. extracted by it to their original form, quality or character.

The peculiar action of the sulfur dioxid on the-heavy hydrocarbons contained in the petroleum renders the operation a practi-' cally continuous one and reduces the consumption or waste of the separating agent to a minlmum; 'The said process involves further the reuse of the reagent over and over again indefinitely, either in treating the same body or charge of oil product of separating from distillates of crude petroleum the undesirable proportion of the aromatic compounds, or heavy hydrocarbons contained therein, consisting in subjectmg the distillates to sulfur dioxid gas under pressure in a closed vessel until precipitation of the heavy hydrocarbon attacked by the gas takes place, then drawing.

off the precipitated matter, separating the sulfur dioxid from such product by the application of heat and restoring the same to a gaseous form, then returning the recovered gas to the distillates and continuing the precipitation of the hydrocarbons in the charge until the desired density or other condition of the oil product is obtained, and finally applying heat to the said product to drive ofl the gas contained in the prodnot and subjecting the same to the usual washing and other treatment to obtain the finished product.

The invention, embraces, further, novel and useful apparatus which I have produced and employ for applying and carrying on the several steps or operations of saturating the oil product, drawing oil the precipitates,

recoverin the reagent therefrom and returning t e recovered reagent I130 the said product under treatment, and controlling the circulation: or cycle. of the reagent by regulating the temperature and the pressure of the gas in a continuous manner.

In the following detailed description I proceed to explain at greater length the na- The waste product or matter obtained by ing represents in elevation and somewhat diagrammatically one form of the apparatus for carrying on the process.

In the drawing a indicates a closed gas tight vessel-such as theagitator of well known construction employed in refining oillined with lead, and provided with a conical bottom 6 in which is an outlet (Z for drawing ofi' the settlings or precipitated matter. For working this process on a large scale and in a continuous manner I employ to advantage two of these agitators, which I connect with a sulfur dioxid gas generator 8, a gas compressor p and an evaporator g in which the precipitates and the gas carried down with them are separated and the gas is recovered for use again.

Through a line of pipesand connections pigle 3.

ach agitator is connected with the gas compressor p through the line of pipe m leading" from the pressure side of the com pressor, and in the connections are valves for shutting off or establishing communication with one or the other at will. The two agitators are also connected directly together by a pipe 30; the valves 22, 23, 2& on one, and others 25, 26, 27 on the other set of connections being arranged in such manner that the spray-pipe h in either agitator can be connected directly with the gas compressor, or with the gas containing space of the other agitator, or else with the gas containing space of the evaporator 9, during the operation. k

The agitators a a a are identical in con- .struction. The bottom I) in each is made of This step is erformed preliminarily to the operations 0 washing and finishing the oil tion when precipitation will take place is supplied to the agitator; then connection with the gas compressor is cutoff and the further supply of gas to keep the conditions up to the point of precipitation is taken from the evaporator. This is done as soon as the evaporator has received a sufficient quantity of the precipitates to furnish the gas and obtain the required degree of pressure in that chamber whereby the gas will be forced into the charge of the oil product in the agitator.

Being connected separately with the gas compressor, the agitators or the evaporator can be charged or replenished with the gas drawn from the generator to replace any loss of gas due to leakage, or to absorption of the gas by the oil product. Connection for such purpose is made between the agitators and the suction side of the compressor 79 through pipes 'v2 entering the upper part of the agitators a; each pipe 2: having a valve 17 for opening or closing communication with the compressor. The spraypipe h in each agitator is connected with the gas containing space of the evaporator through the pipes 31, the same being provided with the valves 22, 23, 24 and 25, 26,

27 and 32.

The gas circulating system, as it may be termed, in this apparatus is arranged as .above described with the view to an economical operation of the two agitators in an alternate manner, by which the effective absorption, separation and reuse of the gas can be carried on continuously.

The outlet (Z is connected with the evaporator 9 through the pipe 2 and from the same outlet also a separate pipe 3 runs to the oil storage tank t. A direct outlet d from the conical bottom Z) is provided for running off the waste matter from the washing and finishing.

The manner of treating a batch of crude material in the form of kerosene or burn ing oil distillates in this apparatus in accordance with my invention I will now proceed to describe with reference to the drawing, andin such terms as will enable a person familiar with the refining of oils to apply and carry on the process. WVhen the charge of the crude material run into the agitator a is the initial charge and there is no pressure of gas, or not a sufiicient pres"- sure of the gas in the separating chambers,

of oil.

connection is made with the gas compressor p by opening the valves 1012', 22-2526 in the conducting pipes and taking the gas from the generator 8 until the charge of material in the agitator has absorbed and becomes saturated with gas to the point or condition of precipitation. As soon as precipitation of the hydrocarbon compounds attacked by the gas takes place and the 'precipitates thrown down are sufficient in quantity to be treated in the evaporator g, the furthei} supply of gas to keep the conditions of the material in the agitator above the point at which precipitation is effected by the gas is obtained from the evaporator g, and connection with the gas compressor is shut off and is established with the evaporator. After the initial saturation of the charge in the agitator is effected by taking the gas from the generator .9 therefor, the required increment to replace the portion which is carried down in the precipitates is obtained and furnished by recovering the sulfur dioxid in the precipitates and returning them into the body of material in the agitator. As soon as the evaporator g has become charged with the gas separated from the precipitates, and the pressure necessary to force the gas over and into the charge of material in the agitator is established at which time in the operation the pressure in the evaporator g obviously must be greater than that in the agitatorthe precipitation can be continued as long as required to obtain the desired grade or quality As the degree of pressure required to force the gas-through .thebody of crude material in the agitator is obviously governed by the depth of that body, as well as by the temperature, it necessary to obtain the initial supply of gas through the gas compressor at suflicient pressure to set up the required saturation and start the precipitation of the heavy hydrocarbon compounds. But when the pressure in the evaporator g is raised to the required degree or condition abovethat in the agitator, T as before described, the sup'ply: of sulfur dioxid need be no longer taken from" the 'gas compressor; and the same is cut off, except as it may .be

found necessary to introduce into the circu-, A

lationior round of'the gas through the agitator and the evaporator from time to' time, or at infrequent intervals, .an additional quantity of the gas to replace any loss due to leaks or otherwise, for the purpose of se 7 in which the precipitates collected in the curing the saturation of the material and I the effective separation and precipitation of conical bottom are indicated by the difference in color between them and the oil product; and as the same collect they are drawn Oil by opening the valve in the connection- 2 between the outlet d and the evaporator wherein the operation of separating andv removing the gas which has been carried down in the precipitates is carried on. As the sulfur dioxid readily separates from the hydrocarbon compounds under a relatively low or -moderate temperature and does not 1 affect or change the character'of those compounds, the use of this gas-as a reagent in treating petroleums of the grades or character before mentioned is found to afford several advantages over the reagents employed in other. processes in which objectionable changes in the extracted bydrocarbons are producedby the chemical action of the reagent employed."

- By means of the steam-coil cheat is applied. to the precipitates collected in the evaporator, and the temperature is raised and maintained at the required degree to "drive ofl the sulfur dioxid and to maintain the pressure in the evaporator and their connections With'the agitator above that existingin the agitator. Such excess of pressure in theevaporator will'be found to give good results by keeping the charge of material in the agitator at normal temperature, or about 60 Fahrenheit, and maintaining the temgle agitator.

perature in the evaporator 9 between 8Q and 85 Fahrenheit; and under those conditions the sulfur dioxid will be driven off and returned to the agitator at a pressure suflicient to maintain a continuous circulation' or movement and use of the gas over 1 and overag'ain. 40

I 7 the apparatus herein described is connected with the two agitators, that it may receive The evaporator g in the arrangement of and treat the precipitates drawn from both. It is also connected with bothagitators by means of the pipes and connections 31m for the purpose of returning-and directing the recovered gas into on'eiagit'atoro, or the other am. With two' agitators .connected with the evaporator and with each other as shown, the charges of crude material can be as can be treated more rapidly and the handledmore economically than witha sin- A fter precipitation is set up in. the agi tator it continues to takeplace as long as gas is forced into the charge'thro'ugh the spraypipe, the hydrocarbons being attacked and removed'bythe gas according to their relative density, 'first'the heaviest of the com pounds and then the. other of less dense quality; so that it is practicable in this process to obtain any desired grade or quality of finished oil product containing a eater or less proportion ofthe heavier hy rocarbon compounds-if it be desirable to retain any such in the productsand any desired degree of gravity can be secured by shutting ofl the further supply of the gas to the agitator at the proper moment, and stopping the precipitation at that point.

The state or condition of the oil product being treated is ascertained by taking samples of the oil product-through the pet cock 5 and testing the same in the usual manner to determine thefiashing point, gravity and other qualities of the oil.

The continuity of the operation of removing the undesirable proportions of the hydrocarbon compounds present in any grade or character of oils is thus always under control, and it can be prolonged or cut off as conditions may require without liability ofso acting on the material as to remove from. it any of the desirable hydrocarbon 1 compounds.

When the required conditions have been obtained in the charge in one agitator the operation is suspended by shutting ofi the gas, and the/charge is then prepared for the usual washing and finishing treatment with acid and alkali, by removing whatever sulfur dioxid remains in the body of oil and in the agitator chamber. I therefore raise the temperature of the charge by means of the steam-coil e in the bottom of the agitator, the precipitates being previously withdrawn from the receptacle 5, and-by the heat thus applied I drive off the sulfur dioxid from the oil and from the chamber in the other agitator.

The outlet at the top of the agitator provided for that purpose being connected with the spray-pipe It in the other agitator through the pipe 30 and connections, the ex- I pelled gas is forced into the body of oil con tained in the other agitator, to be absorbed with a receptacle for the gas, when the sec ond agitator is not employed.

In the arrangement of the apparatus shown in the drawing one agitator isconthe spray-pipe of the agitator ad by opening closed; The'removal of the gas from the agitator at such time is also expedited by 'working the gas compressor p and drawn. g -off the gas through the connections in the a line of pipe 0 v m on connecting the agitator a with the suction side of the compressor, and forcing it through the pipe m'leading from {the pressure side to the spray-pipe h in the agitator aa; this means of removing the expelled gas from the agitator m is resorted to when the temperature the agitator is no longer sufl'icient to maintain the pressure at the expelling or driving off point.

the temperature of the oil for that purpose thereby; or, by establishing communication the connections 27-28, the valve 24 being nected with the other by the pipe 30 when ,ever gas. is expelled from the agitator a into It is generally undesirable to raise,

I mea re above 125 Fahrenheit, on account'of the liability to throw the finished product off color, connection is therefore made with the gas compressor at or before the temperature of the oil reaches that point. As the temperature of the oil is also subject to an increase during the first part of the process, during which the gas is supplied from the evaporator, it becomes necessary to counteract such rise in temperature, that the oil may remain as nearly as practicable at normal temperature, or sufiiciently below the temperature existing in the evaporator to secure the proper circulation or cycle of the gas during the precipitating process. This condition is produced accordingly by providinga cooling c'oil w in the agitator chamber,through which water is caused to circulate by connecting the coil with a servicepipe. The How and circulation of the gas is thus efiected and maintained by regulating and varying the temperatures existing in the agitator and the evaporator, raising the temperature in one, or reducing it in the other chamber as conditions require. The usual pressure gages are provided on the apparatus to guide the operative in maintaining the working conditions.

Thee separated hydrocarbon compounds are run off from the evaporator into a storage-tank y wherein they are collected for such treatment as'may be required to prepare them for future purposes and uses.

I claim 1. The improvement .in refining a liquid, as oil, by means of an agent, as sulfur dioxid, which is aeriform under atmospheric pressure at temperatures above the freezing point of water and which unites at such temperatures under appropriate superatmospheric pressures when in suitable proportion with constituents of said liquid to form compounds that separate by gravity'from the remainder of said liquid and that liberate said agent in aeriform condition when heated, which improvement-consists in subgec ting liquid to be refined tosaid agent at a temperature above the freezing point of water in sufficient proportion and under suflicient superatmospheric pressure to form such compounds at the treating temperature, withdrawing the so formed compounds from the remaining liquid, heating theso withdrawn compounds in such manner as to liberate said agent therefrom inaeriform condition under superatmospheric pressure sufficient to form such compounds at a. temperature above the freezing point of, water, conveying the so liberated agent underfsuch a superatmospheric pressure resulting in its entirety from said heating operation, and subjecting liquid to be refined to said agent in sufficient proportion under the so resulting pressure at atemperature above the freezing point of water and suitably correwhich pressure at temperatures above the freezlated with said pressure so as to form such compounds, substantially as described.

2. Apparatus for refining a liquid, as oil, by means of an agent, assulfur dioxid, which is aeriform under atmospheric pressure at temperatures above the freezing point of water and which unites at such temperatures under appropriate superatmospheric pressures when in suitable proportion with constituents of said liquid to form compounds that separate by gravity from the remainder of said liquid and that liberate said agent in aeriform condition when heated, which apparatus consists of appliances for subjecting liquid to be refined to said agent at a temperature above the freezing point of water in suflicient proportion and under sufficient superatmospheric pressure to form such compounds at the treating temperature,

appliances for withdrawing from the remaining liquid the compounds-so formed by means of the first mentioned appliances, appliances for heating the so withdrawn compounds in such manner as to liberate said agent therefrom in aeriform condition under.

superatmospheric pressure suflicient to form such compounds at a temperature above the freezing point of water, and appliances for conveying the so liberated agent under such a superatmospheric pressure resulting in its entirety fromthe heating performed with the aid of said heating appliances and for subjecting liquid to be refined to said agent in suiii'cient proportion under the so resulting pressure at a temperature above the freezing point of water and suitably correlated with said pressure so as to form such compounds, substantially as described.

3. The improvement in refining a liquid, as oil, by means of an agent, as sulfur dioxid, is aeriform under atmospheric ing point of water and which unites at such temperatures under appropriate superatmospheric pressures when in suitable proportion with constituents of said liquid to form compounds that separate by gravity from the remainder of said liquid and that liberate said agent in aeriform condition when heated, which improvement consists in subjecting liquid to be refined to said agent} at a temperature above the freezing point of water in sufficient roportion and under sufiicient superatmospheric pressure to form such compounds at the treating temperature, withdrawing the so formed compounds from the remaining liquid, heating said remaining liquid to a temperature not exceeding about 125 F. in, such manner as to liberate therefrom a part of its content of said agent in aeriform condition under superatmospheric pressure sufficient to form such compounds at a temperature. above the I freezing point of water, conveying the so lib- 19W 7 heating operation, subjecting liquid to be refined to said agent in suflicient proportion under the so resulting pressure at a temperature above the freezingpoint of Water and suitably correlated to said pressure so as to form such compounds, and later heating said remaining liquid at the specified temperature under a reduced pressure in orderto get off another part of its content of said agent, substantially as described.

4. Apparatus for refining aliquid, as oil, by means of an agent, as sulfur dioXid, which is aeriform under atmospheric pressure at temperatures above the freezing 7 point of Water andWhich unites at such temperatures under appropriate superatmospheric pressures when in suitable proportion With constituents of said liquid to form compounds that separate by gravity from the remainder of said liquid and that liberate said agent in aeriform condition When heated, Which apparatus consists of appliances for subjecting liquid to be refined to said agent at a temperature-above the freezing point of Water in sufficient proportion and under sufiicient superatmospheric pressure to form such compounds at the treating temperature, appliances for Withdrawing froin the remaining liquid the compounds so formed by means of the first mentioned appliances, heating appliances for raising the temperature of said remaining liquid to one not exceeding about 125 F. in such manner as to liberate a part of its content of said agent in aeriform condition under superatmospheric pressure sufficient to form such compounds at a temperature above the freezing point of Water, appliances for conveying the so liberated agent under such a superatmospheric pressure resulting in its entirety from the heating performed with the aid of said heating appliances and for subjecting liquid to be refined to said agent in suificient proportion under the so resulting pressure at a temperature above the freezing point of Water and suitably correlated With said pressure so as to form such compounds, and appliances whereby the heating of said remaining liquid can later be performed at the specified temperature under a reduced pressure in order to get off another part of its content of said agent, substantially as described.

JOHN C. BLACK. Witnesses:

EDWARD E. OSBORN, M. REGNER; 

